Updated 10:14 am ET Anyone thinking senators would return from last week’s elections inspired by voters’ desire for problem solving and cooperation has gotten a strong dose of reality in the first two days since the Senate came back into session this week.

Despite the talk of the need for bipartisan solutions, inflammatory issues were already dividing senators, chief among them the pending tax increase set to occur at year end and the investigation of the Sept. 11 attack on the U.S. consulate in Benghazi which resulted in the deaths of four Americans, including Ambassador Chris Stevens.

Voters dislike the impasses and the bitterness, most senators agree. Sen. Bob Casey, D-Pa., who won a second term last Tuesday, said, “The main message I heard throughout the state ... is they expect folks to go back to Washington and work together – I heard that over and over again.”

Sen. Dick Durbin, D-Ill., joins Morning Joe to discuss if he believes Senate and House Republicans will be more willing to negotiate a deal to avoid the fiscal cliff than they were in 2011.

And to be sure, there are some signs of bipartisan courtesy and warmth: Democratic Sen. Tom Harkin paid tribute on the Senate floor Wednesday to his Iowa Republican colleague Sen. Charles Grassley, who had just cast his 11,000th vote as a senator.

And Sen. Bob Corker, R-Tenn., was seen in a brotherly bipartisan shoulder embrace with Sen. Chris Coons, D-Del., as they walked down a hallway Tuesday in the Capitol.

“I’m still very hopeful” that Congress can agree before Dec. 31 to a bill to reduce spending and raise tax revenue, Corker said Wednesday.

Corker said a bill to impose a $50,000 cap on itemized tax deductions can be short and simple. “It’s a paragraph – what’s so hard about that?” he asked.

But even if Corker’s optimistic forecast on a fiscal accord is right, plenty of fuel remains for partisan firestorms.

Sens. John McCain, R-Ariz., Lindsey Graham, R-SC, and Kelly Ayotte, R-NH, hold a news conference to discuss the Sept. 11th, 2012, attack on the U.S. consulate in Benghazi, Libya.

On Wednesday, a trio of GOP senators, led by Sen. John McCain, R-Ariz., renewed its call for a special Senate select committee to investigate the Benghazi attack, which Sen. Lindsey Graham, R-S.C., called “a national security debacle long in the making.”

(McCain's proposal was rebuffed Wednesday by several senators, especially some Republicans who serve on the Senate Intelligence Committee such as Sen. Richard Burr of North Carolina who said, "Listen, I think it's way too early to be calling for a special committee.")

McCain, Graham and Sen. Kelly Ayotte, R-N.H., also said they would oppose President Barack Obama if he nominates U.N. Ambassador Susan Rice to replace Clinton as secretary of state.

They believe Rice should not have claimed on NBC’s "Meet the Press" that the Benghazi attack was a reaction to an inflammatory anti-Islamic video and that she should have known it was a terrorist attack.

U.S. Ambassador to the United Nations Susan Rice recaps the causes and effects of recent violence against Americans in the Middle East.

Even as he was firing a shot across Obama’s bow on a potential Rice nomination, Graham used some bipartisan rhetoric on the Benghazi investigation: “I am urging Democrats and Republicans to put aside any partisanship we may have in this new Congress on Benghazi and find a way forward.”

He also praised Senate Intelligence Committee Chairwoman Sen. Dianne Feinstein, D-Calif., even though he contended that no one committee could have the comprehensive view of the events needed to get to the truth. “Dianne Feinstein has been terrific. It’s not that I don’t trust Dianne; she’s doing a great job. But she cannot know what the Armed Services Committee may find out.”

But Graham also sounded combative in challenging Rice and Obama: “Somebody has got to start paying a price” for what occurred in Benghazi and in the administration’s explanation that followed it.

Karen Bleier / AFP - Getty Images

Republican Sens. John McCain, Lindsey Graham and Kelly Ayotte hold a press November 14 regarding the terrorist attack in Benghazi, Libya on September 11, 2012.

“I don’t trust her,” Graham said of Rice, calling her “more a political operative than she is anything else when it comes to Benghazi.”

The South Carolina Republican may have waved a red flag at Democrats when he compared the special committee he and his GOP colleagues are proposing for Benghazi to the ones created in 1974 to probe the Watergate break-in and in 1986 to examine the Iran-Contra arms-for-hostages scandal.

He added later: “Don’t call it Watergate if that makes you mad, makes you upset. Call it the 9/11 commission; call it the Iraq Study Group” — previous cases in which bipartisan blue-ribbon investigations were conducted.

Obama came to Rice’s defense in his Wednesday afternoon press conference about two hours after McCain, Graham and Ayotte spoke. “To besmirch her reputation is outrageous,” he said.

Not letting Obama have the last word, McCain was on the Senate floor a few hours later, renewing his call for the special committee and disputing Obama’s contention that he and his allies were picking on Rice.

Meanwhile, legislation on the tax increase and other matters await action.

And the Senate centrists who make compromises possible are vanishing, lamented Sen. Scott Brown, R-Mass., Tuesday in the wake of his defeat last week by Democrat Elizabeth Warren.

Snowe, Conrad, and Lieberman are retiring at year's end, and both Brown and Lugar were defeated this year, with GOP primary voters booting Lugar out last May.

"That group in the middle — it's vanishing,” Brown said sadly. “And on both sides there are extremes kind of pushing back against the middle, but I’ve always felt that that group in the middle is quite frankly the most powerful group because they have the ability to get to that 60-vote threshold and actually get things done,” Brown told reporters.

He added that in his final weeks in the Senate, “I’m hopeful that, being that bipartisan guy, that I can continue to bring people together and look at ways to solve our country’s problems.”

But if voters really want centrists, pragmatists and lawmakers willing to compromise, as Brown and Casey both say they do, then why did Massachusetts voters dump Brown in favor of Warren, a markedly more left-leaning replacement?

Is it that voters don’t really want centrists or did Brown simply not persuade them that he is one?

Senate Majority Leader Harry Reid reacted disdainfully on Wednesday to Brown’s comments, contending that the Massachusetts Republican was neither a genuine centrist nor a bridge builder between the parties.

“I saw during the campaign his plea for bipartisanship,” Reid scoffed. “That is a big joke. It’s a travesty. He was one of the most partisan people that’s ever served here.”

Reid said Brown “could have saved” a Democratic bill to limit the effect of the Supreme Court’s Citizens United decision, which allows greater corporate and labor union money in running campaign ads.

“He could’ve been the sixtieth vote on that and many other things, so I don’t need a lecture from him on bipartisanship,” said Reid. “He should go look in a mirror.”

The winner of a stunning 2010 special election and the first Republican elected to the Senate from Massachusetts since 1972, Brown ranks almost in the middle in the National Journal’s annual ideological ranking of all senators. He is ranked 45th most conservative, close to Snowe, Sen. Mark Pryor, D-Ark., and Sen. Ben Nelson, D-Neb., who is also retiring at the end of this year.

But Brown sided with his party on high-profile votes such as opposing the effort to undo the Citizens United ruling and voting against confirmation of Obama’s nomination of Elena Kagan to the Supreme Court. He cited Kagan’s lack of judicial or courtroom experience.

And on tax increases, Brown Tuesday sounded like a staunch Republican: “All I know is that wherever I went (during his re-election campaign) people were tired of giving more of their hard earned money to the federal government – knowing they waste a lot of it.”